Postoperative Resuscitation

Abstract

You have just completed a major damage control operation with significant blood loss and ongoing resuscitation. As the patient rolls through the ICU doors, you are asked to write orders for the nurses to begin the postoperative care phase. You may or may not have an “intensivist” available to help you. Having a clear vision and plan for performing and monitoring the postoperative resuscitation is critical to avoid the twin evils of under-resuscitation and over-resuscitation. In combat surgery this is particularly critical as you often have to hand the patient off to the nurses or another physician and return to the ER or OR. Having a general approach or “philosophy” to resuscitation that the nurses, surgeons, and other physicians agree with and understand can make this process much smoother and less confusing.

Civilian Translation of Military Experience and Lessons Learned

• Andrew C. Bernard 

Key Similarities

• Resuscitations often change hands in civilian practice, so directions and transitions of care have to be clear and accurate.

• Over- and under-resuscitation can occur and are equally bad.

• Those failing resuscitations are probably bleeding.

• Goals are the same – resolve acidosis and restore normothermia, coagulation, and oxygen delivery/consumption.

• Blood products should be the primary postoperative resuscitation fluids.

• Base deficit and lactate are the overall best measures of resuscitation.

Key Differences

• A myriad of monitoring tools are available which can tempt the provider into focusing too heavily on numbers and devices rather than examining the patient, assimilating information, and making decisions.

• Misguided use of albumin is more common in the civilian trauma resuscitation because the civilian environment is not as resource-limited.

Civilian postoperative resuscitation follows the same principles as those outlined by Dr. Schreiber. This includes resolving acidosis and restoring normothermia, as well as restoring normal coagulation and normal oxygen delivery/consumption. All of these goals are sought simultaneously and on a continuum as in the military environment, but the fragmentation inherent in US trauma systems creates discontinuity and unique challenges in achieving this goal. Continuous resuscitation can be more, not less, difficult in the civilian setting.

Resuscitative fluid choice and volume has gained much attention, and the ATLS now supports a smaller initial fluid bolus and earlier assessment of whether the patient has ongoing hemorrhage. “Hypotensive resuscitation” is taught in the ATLS and in our training programs and has been practiced more in the last decade. But the most appropriate population and situation for “hypotensive resuscitation” are still unclear. Historically the blunt-injured patient with a possible head injury facing a long transport time was thought not to be a candidate for hypotensive resuscitation, while the penetrating-injured patient in a major trauma center with a very short door-to-OR time was thought to be ideal. But recent evidence from the original proponents of hypotensive resuscitation questions the superiority of this resuscitation strategy over a more standard blood pressure target (MAP =65 mmHg). In the average emergency department (ED) in the USA, the initial fluid will and still should be crystalloid. More important is what happens after the crystalloid bolus. The characteristics of nonresponders, transient responders, and responders indicate the likelihood of ongoing bleeding and dictate the next fluid to be used. Non- and transient responders in the emergency department need blood. In postoperative resuscitation, blood component therapy is even more likely to be the best choice. Fresh whole blood remains impractical and of questionable benefit in the civilian setting. The recently published PROPPR Trial demonstrated that a balanced hemostatic resuscitation with a plasma/platelet/RBC ratio approaching 1:1:1 will produce more survivors at 24 h than a lower ratio of plasma and platelets to RBC (1:1:2 or lower).

Colloids have no more benefit in civilian postoperative resuscitation than in military resuscitation. But because the civilian environment is resource-rich, albumin use is much greater. Most civilian surgeons would be surprised to find out how much albumin is administered to their trauma patients by anesthesia and by their less-informed but well-intentioned residents and staff. We have admonished our teams for giving too much crystalloid, so they sometimes turn to albumin as an alternative. A quick look at one’s hospital pharmacy data, searched by attending name or by service, will be eye opening to many surgeons and serve as a basis for reducing unnecessary and expensive albumin use. Albumin does nothing to enhance urine output and only contributes to accumulation of extracellular fluid, rather than preventing it.

Monitoring resuscitation in the civilian setting is best done with eyes, ears, hands, and basic laboratory tests, just as in the military setting. However, a myriad of monitoring systems are available and thus are used and misused. Base deficit and lactate are the best overall measures of resuscitation. Just as in the military setting, they should be obtained immediately upon arrival in the postoperative care area and trended until normal, an endpoint best reached within 24 h. CVP is notoriously inaccurate for all the same reasons articulated by Dr. Schreiber. The primary value of a central line is to administer blood and to monitor central venous oxygen saturation as an indirect measure of oxygen delivery. Despite recent criticism of continuous venous oxygen saturation as a resuscitation target in the critically ill septic patient, tissue oxygenation remains the fundamental physiologic goal in ICU patients, especially those who are injured and bleeding. The question one should ask oneself at the bedside is how best to measure oxygen delivery. Tissue oxygen saturation can be measured noninvasively via near-infrared spectroscopy and predict blood product requirement and need for surgery. Aside from measuring oxygenation via lab tests and tissue saturation, all other resuscitation tools measure plasma volume or flow. Cardiac and/or caval ultrasound is perhaps the most popular new method of assessing volume status, but it is highly user- and image-dependent. Analysis of the arterial waveform in ventilated patents can be used to assess volume responsiveness, but this has not been tested in trauma, is interpreter-dependent, and requires arterial cannulation and mechanical ventilation. Measures of plasma volume and arterial waveform amplitude still only measure one component (stroke volume) of one component (cardiac output) of the oxygen delivery equation, not whether the tissues are actually receiving and consuming oxygen adequately.

Vasopressors should not be necessary for most trauma victims, and Dr. Schreiber’s admonition is equally true in the civilian trauma ICU: failure of a patient to respond appropriately to resuscitation is most often a sign of ongoing hemorrhage that warrants reoperation or some other intervention for hemorrhage control. However, select patients in whom bleeding is not severe, and are more neurologically injured, will benefit from vasopressor use for limited intervals during early resuscitation. Established scientific evidence to support vasopressors in bleeding patients is still lacking, and no randomized prospective data support their use.

“Saltwater drowning” occurs in civilian trauma resuscitation with equal or greater frequency than in military settings because modern resuscitation paradigms germinated in theaters of war take time to establish themselves as standards across the US civilian data support a ratio of less than 1.5:1 for crystalloid: RBCs in reducing MOF, ARDS, and abdominal compartment syndrome though not all authors agree that crystalloids are such the culprits they have been portrayed to be. Civilian surgeons are, however, catching on to fluid restriction. Temporary closure of the abdomen after trauma is less common today as a result. Abdominal compartment syndrome has become uncommon compared to the past.

Civilian resuscitation should follow the same principles as it does in the hands of our military colleagues. Careful transition of care out of the operating room; liberal use of blood components until temperature, coagulation, acidosis, and oxygen delivery normalize; high index of suspicion for ongoing bleeding; consistent and systemic use of the reliable resuscitation targets like serum lactic acid; and avoidance of over-resuscitation are the fundamental principles. We in the civilian setting must not let our ready access to a myriad of monitoring devices and too many unnecessary adjuncts like albumin cloud our judgment, distract us, and simply inflate the cost of good trauma care.